Its use as a weapon is limited by subatomic fusion that occurs when the beam of a lasgun (offensive weapon) intersects that of a shield using the Holtzman field (defensive weapon). See the blaster (1925) from When the Green Star Waned by Nictzin Dyalhis, the neutron blaster (1951), from The Complete Paratime, by H. Beam Piper and the heat ray from The War of the Worlds (1898), by H.G. Wells.